This invention relates to magnetically responsive composite materials. More particularly it relates to magnetically responsive composite microparticles having a permeable, solid, water-insoluble matrix comprising a proteinaceous material, a polysaccharide or mixtures thereof.
Water-insoluble proteinaceous or polysaccharide microparticles are known. For example, U.S. Pat. No. 3,663,685 describes physiologically acceptable parenterally metabolizable protein or polysaccharide microparticles. U.S. Pat. Nos. 3,663,686 and 3,663,687 each describe physiologically acceptable, parenterally metabolizable protein microparticles while U.S. Pat. No. 3,758,678 describes physiologically acceptable, parenterally metabolizable polysaccharide microparticles. These microparticles are, or can be made, radioactive and can be employed for diagnostic, prophylactic or therapeutic purposes.
Water-insoluble protein or polysaccharide microparticles have also found use in labeling medicaments so that the source of the medicament can later be identified. They have also been used as carriers for various drugs.
Such microparticles have been well accepted. The present invention, however, provides an improvement thereover.